1. Field of the Invention
The present invention relates to a method and system for controlling operation of a hand-held portable cellular telephone, and more particularly to a method for controlling a switchover of an operation mode of an integrally combined television (TV) and portable cellular phone (hereinafter, referred to as “TV phone”).
2. Description of the Related Art
In recent years, rapid and wide spread use of portable cellular telephones as a personal communication appliance has driven development of portable phones with a variety of functions in addition to a simple conversation function. For example, portable phones have developed to include a calculator, a biorhythm checking feature, and the capability of transmitting and/or receiving images of a TV and a video camera. The term “TV phone” herein refers to wireless portable cellular phones of all types which also provide television (TV) broadcast through a display unit of the portable phone, in addition to a cordless telephone conversation feature for telecommunication.
An example of the above TV phone is disclosed in Korean Patent Application No. 1995-46026 entitled “A Combined TV Receiver and Cellular Phone” by LG Electronics Co., Ltd., filed in the Korean Industrial Property Office on Dec. 1, 1995 and published on Jul. 31, 1997 by that Office.
For reception of a TV broadcast, the portable phone is equipped with two radio frequency units therein, as disclosed in the above-mentioned Korean patent application 1995-46026. The reason for this is that a frequency bandwidth necessary for transmitting and receiving telecommunication messages (i.e., voice and data) is different from that for a TV broadcast. An operation mode of the TV phone is classified into a phone mode, a waiting mode, and a TV mode, which is also used as the waiting mode. When operating in the TV mode, the TV phone allows a user to watch and hear images and voices of the television program received on a display unit, i.e. a Thin Film Transistor (TFT) Liquid Crystal Display (LCD), and a speaker or an earphone of the portable phone.
Disadvantages arise in the prior art when the TV phone is operating in the TV mode and there is an incoming call and/or an incoming character data message.
There is a need for a portable TV phone that allows the operation mode of the TV phone to be automatically switched from a TV mode to a phone mode so that the user (i.e., the called party) can speak over the telephone with the calling party and the circuitry associated with the TV function can be disabled in order to prevent unnecessary consumption of the battery during the ensuing phone conversation. In addition, there is a need for a portable TV phone that allows the user to reject the incoming call in order to continue to view the TV program when the user does not care to respond to the incoming call.
The TV phone of the above-cited patent application 1995-46026 cannot process character messages received by the transmitter/receiver of the telecommunications feature when the TV is operating in TV mode and receiving a TV signal via the receiver of the TV. In addition, when the TV phone of patent application 1995-46026 receives an incoming voice call, the telephone rings, but it is impossible to directly switch the TV mode to the phone mode while in the TV mode. Accordingly, the user must turn off the TV phone, manually switch the TV mode to the phone mode with regard to every incoming call, and turn the phone back on. This consumes battery power and is highly inconvenient to the user.